SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13499b5cc590a4d344b0778336cf9e12fcc69fec30bf5327321218541572290c' 
  AND token = 'X504xXG1IvMKh2iuwvGFwuO/iPKC+cD32k+f6Isu3S0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}